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Re: Sort lines in a plain text file alphanumerically

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On 08/05/2013 10:19 PM, MRAB wrote:
> On 06/08/2013 03:00, Devyn Collier Johnson wrote:
>> I am wanting to sort a plain text file alphanumerically by the lines. I
>> have tried this code, but I get an error. I assume this command does not
>> accept newline characters.
>>
>>
>>   >>> file = open('/home/collier/pytest/sort.TXT', 'r').read()
>
> That returns the file as a single string.
>
>>   >>> print(file)
>> z
>> c
>> w
>> r
>> h
>> s
>> d
>>
>>
>>   >>> file.sort() #The first blank line above is from the file. I do not
>> know where the second comes from.
>> Traceback (most recent call last):
>>     File "<stdin>", line 1, in <module>
>> AttributeError: 'str' object has no attribute 'sort'
>>
> Strings don't have a sort method.
>
>> I had the parameters (key=str.casefold, reverse=True), but I took those
>> out to make sure the error was not with my parameters.
>>
>> Specifically, I need something that will sort the lines. They may
>> contain one word or one sentence with punctuation. I need to reverse the
>> sorting ('z' before 'a'). The case does not matter ('a' = 'A').
>>
>> I have also tried this without success:
>>
>>   >>> file.sort(key=str.casefold, reverse=True)
>> Traceback (most recent call last):
>>     File "<stdin>", line 1, in <module>
>> AttributeError: 'str' object has no attribute 'sort'
>>
> Try this:
>
> lines = open('/home/collier/pytest/sort.TXT', 'r').readlines()
> lines.sort()
>
>
> Actually, a more Pythonic way these days is to use the 'with' statement:
>
> with open('/home/collier/pytest/sort.TXT') as file:
>     lines = file.readlines()
>
> lines.sort()
>

Thanks! That works well. After I run your command, I run

print(''.join(lines))

to get the sorted output. Even the parameters work without issues.

lines.sort(reverse=True, key=str.casefold)


Mahalo,

DCJ

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Re: Sort lines in a plain text file alphanumerically Devyn Collier Johnson <devyncjohnson@gmail.com> - 2013-08-06 06:35 -0400

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